structure and function of the hand Flashcards
what is the flexor retinaculum?
thickening of the deep fascia, it stretches across palmar surfaces of carpal bones
how is the flexor retinaculum attached?
medially to pisiform &hook of hamate.
Laterally to scaphoid & trapezium.
what is the palmar aponeurosis
triangular in shape and occupies central part of the palm
how does the palmar aponeurosis attach
tip attaches to distal border of flexor retinaculum
– It receives insertion of tendon of the palmaris longus
– Its base is divides into 4 slips which fuse with fibrous flexor sheath and deep transverse ligaments
what is the function of the palmar aponeurosis
Improves grip strength.
It protects the underlying
structures in the palm.
what is the name of the deformity resulting in fibrosis of the palmar aponeurosis
Dupuytren’s contracture
what is the effects of the dupuytrens contracture
Thick, scar-like tissue forms under the skin of the palm and may extend
into the fingers, pulling them toward the palm and restricting motion.
what are some treatments of dupuytrens contracture
- Stretch.
- Steroids & enzymes injection.
- Radiations.
- Needle aponeurotomy.
what does the carpal tunnel transmit
- Median nerve.
- Flexor digitorum superficialis & profundus tendons with the
synovial sheath (ulnar bursa). - Flexor pollicis longus tendon with its synovial sheath (radial
bursa) - Flexor carpi radialis tendon with its synovial sheath.
the muscles of the thumb are made up of thenar muscle group and adductor pollicis. what is this group made up of
- Abductor pollicis brevis
- Flexorpollicisbrevis
- Opponens pollicis
thenar muscle have a common origin what is it?
Common Origin:
Flexorretinaculum & trapezium.
what is the origin and insertion points of adductor pollicis
Origin: Palmar surface of 2nd & 3rd metacarpals.
Insertion:Medial side of base of proximal phalanx of thumb.
what are the origin and insertion points of palmar brevis
Origin:Palmar aponeurosis
Insertion:Skin on the medial margin of the hand.
what is the origin points of
- Abductor digiti minimi
- Flexordigitiminimi
- Opponensdigitiminimi
they share a common origin:Flexor retinaculum & hamate
what are the insertion points of
- Abductor digiti minimi
- Flexordigitiminimi
- Opponensdigitiminimi
- Abductor digiti minimi:Base of proximal phalange of little finger medially.
- Flexor digiti minimi: Base of proximal phalange of little finger
- Opponens digiti minimi:Medial margin of metacarpal
what is the origin of the lumbrical muscles(4 small, cylindrical muscles for the medial 4 fingers)
1st & 2nd from lateral sides of tendons of flex. dig. Prof.
3rd & 4th from adjacent sides of tendons of flex. dig. Prof.
what is the insertion of the lumbrical muscles
common insertion point:extensor expansions
what is the action of the lumbrical muscles
They flex the metacarpo- phalangeal joints and extend the inter- phalangeal joints (the writing position).
where is the origin of palmar interossei muscles
1st & 2nd from the medial side of first & second metacarpals
respectively.
4th & 5th from the lateral side of the fourth & fifth
metacarpals respectively.
where is the insertion of palmar interossei muscles
extensor expansions
what are the actions of palmar interossei muscles
- Like the lumbricals.
- Adduct the thumb, index & the little ,ring
fingers towards the central axis which pass through the middle finger around which the other fingers move.
what is the origin of the dorsal interossei muscles
- Like the lumbricals.
2. Abduct the index, middle & the little, ring fingers from the central axis which pass through the middle finger.
what nerve supplies to the palmar and dorsal aspects of medial 1/3 of hand & medial 1 ½ digits.
the ulnar nerve
what part of the hand does the median nerve suply
Sensory to skin of the lateral 2/3 of the palmar aspect of hand & lateral 3 ½ digits (including dorsal aspect of their distal phalanges).
Motor to thenar muscles &lateral 2 lumbrical muscles.
what part of the hand does the radial nerve supply
It supplies the skin of lateral 2/3 of the dorsal surface of the hand & the skin of the dorsal surface of the lateral 3½ fingers except the distal phalanges which are supplied by median nerve.
which 2 arteries form the deep palmar arch in the hand
It is formed by the radial artery and the deep palmar branch of the ulnar artery.
where is the deep palmar arch located
It is located between the long flexor tendons and the metacarpal bones.
which 2 arteries form the superficial palmar arch
It is formed by the ulnar artery and the superficial branch of radial artery. .
where is the superficial palmar arch located
It is located between the palmar aponeurosis and long flexor tendons.
how is the dorsal venous network of the hand drained
Dorsal venous network drains proximally into cephalic vein laterally and basilic vein medially.
what causes carpal tunnel syndrome
increase size of some of the structures passing through the tunnel e.g. excessive exercise of the fingers , trauma»_space; swelling/infection»_space; compression of the median nerve.
what would be the your diagnosis if a patient came in with Weakness in thenar muscles (recurrent branch).
Numbness and tingling in the lateral 3 ½ fingers.
The palmar aspect of the lateral 2/3 of hand is spared because palmer cutaneous nerve is spared because it passes superficial to the retinaculum.
these symptoms of carpal tunnel syndrome
how do we treat carpal tunnel syndrome
Immobilization and ice
Surgery to increase space in the tunnel.
